Create

Setting up

1. Install the module
2. Clear the cache
3. Navigate via admin menu to content type, structure, then pick a content type
4. Notice a new tab called "Manage Dependencies"
5. Click on the tab
6. Select the target field i.e. the field that will be disabled or enabled
7. Select the controlled by field i.e. the field that will cause the field from step 6 to be changed.  Usually a checkbox field
8. Select Description i.e. visibility.  e.g. The target field is visible
9. Select "when the control field" value e.g. is checked
10. Save

To test

1. Edit a node of your content type above
2. check the checkbox field specified in step 7
3. Notice that the target field in step 6 appears when the checkbox is checked and immediately disappears when it is unchecked.